Water flows at 600 ft3/s in a rectangular channel 22 ft wide with n 0.024 and a

Question:

Water flows at 600 ft3/s in a rectangular channel 22 ft wide with n ≈ 0.024 and a slope of 0.1°. A dam increases the depth to 15 ft, as in Fig. P10.124. Using gradually varied theory, estimate the distance L upstream at which the water depth will be 10 ft. What type of solution curve are we on? What should be the water depth asymptotically far upstream?